1. Field of the Invention
The invention relates to methods and apparatus for contacting the lead of an article and, more particularly, to methods and apparatus for contacting the leads of an electronic component for electrically testing the component.
2. Description of the Prior Art
In the manufacture of semiconductor devices, semiconductor chips containing the active elements are bonded to a substrate containing a conductor pattern which extends to a pair of opposite edges of the substrate. Leads are bonded to the conductors at these edges and the assembly is encapsulated in plastic. This provides a packaged semiconductor device having two rows of leads. Hence, such a device is commonly referred to in the industry as a dual-inline package.
The leads of the package must be contacted for test purposes. However, like many electronic devices, the leads are quite flexible and unable to resist without support the force required for good electrical contact.
In some cases the support is obtained by inserting the package in a carrier which provides a support surface on one side of a lead while a pair of contacts presses against the other. Operating the contacts in pairs permits one to carry a large current while the other carries a small current. However, having to insert and remove the package from a carrier or other form of support to achieve the desired electrical contact is inconvenient and costly.
In other cases, the contacts are opposed and contact opposite sides of the leads with equal force. These contacts are spread apart against spring tension to permit insertion of the leads and released to make contact. These contacts touch when no lead is in position between them and short the electrical test circuits. There is a direct connection from one contact to the other just as there is when a lead is in position. This precludes the possibility of detecting a missing lead.